3.0 kV β-Ga2O3-Based Vertical p-n Heterojunction Diodes With Helium- Implanted Edge Termination

We demonstrated the vertical NiO/ $\beta $ -Ga2O3 p-n heterojunction diodes (HJDs) with a high breakdown voltage ( ${V}_{\text {BR}}\text {)}$ of 3000 V and a low on-resistance ( ${R}_{\text {on, {sp}}}\text {)}$ of 3.12 m $\Omega \cdot $ cm2, resulting in a Baliga’s figure of merit (FOM) of 2.88 GW/cm2. Specifically, an efficient and low-damage edge termination (ET) formed by the implantation of lightweight Helium atoms was introduced to inhibit the high electric field at the p-n junction of HJDs, thereby increasing ${V}_{\text {BR}}$ of devices from 1330 to 3000 V. The reverse leakage mechanisms were fit and analyzed, revealing distinct breakdown mechanisms in He-implanted devices. The simulation results confirmed the peak electric field at the p-n junction of devices can be effectively suppressed by He-implanted ET. Meanwhile, a narrow change of devices’ ${R}_{\text {on, {sp}}}$ occurred after He implantation and the low- ${R}_{\text {on, {sp}}}$ forward conduction of devices was confirmed by efficient charge transfer of heterojunction with density functional theory (DFT) calculation. This work may provide a new insight into the design and fabrication of high-power, low-loss $\beta $ -Ga2O3 bipolar power devices.